TBM 'Greater Bay Area' has a diameter of 13.32 meters and length of 133 meters. Its cutterhead is designed with the pattern of 'Dragon Going out to Sea'. The machine will be used for the construction of the Pearl River estuary tunnel of Shenzhen-Jiangmen Railway located between Guangzhou and Dongguan. The tunnel that spans 13.69km has been designed to have a maximum depth of 115m and maximum water pressure of 1.06 mPa, over 10 standard atmospheric pressure, making this underwater tunnel top China in this term. It is a one-tube two-lane high-speed railway tunnel with a designrf speed of 250 km/h.
The tunnel underpasses the Pearl River through composite strata such as silt, sand layer and slightly weathered granite, as well as long-distance fault zone, with rock strength cup to 200 MPa. Given the construction difficulty and high safety risk caused by intricate geology and severe water corrosion in the surroundings, the tunnel is listed as the key engineering of Shenzhen-Jiangmen Railway Phase II project.
According to the characteristics of the project, 'Greater Bay Area' is equipped with innovative technologies such as small spacing atmospheric pressure composite cutterhead, retractable main drive, ultra-high pressure automatic compensation, four-circuit pressure maintaining and air cushion straight tunneling system, which guarantee the subsequent safe and efficient construction.
